This invention relates to an indexable marking apparatus, and particularly to such an apparatus for repetitive stamping of indicia or hot metal products.
In the past railroad rails and rolled structural products have been marked by a wheel containing stamps for impressing a heat number, ingot number and perhaps cut number repetitively into the product while it was still hot from the rolling operation. The stamps were contained in a clamping device in the wheel. Changing characters required unclamping the stamps, and manually removing them from the wheel and installation of ones with different characters, or in some cases removal of the entire wheel and replacement with one containing different stamps. Examples of such apparatus are shown in U.S. Pat. No. 3,163,106 Failor, U.S. Pat. No. 3,366,041 Kryorytzky, U.S. Pat. No. 3,800,696 Goto et al., and U.S. Pat. No. 4,036,127 Speicher. Obviously changing characters was time consuming and could cause considerable delay and perhaps loss of production on the mill.
Indexing of characters in rotary printers for marking paper or soft materials is known. However, these devices are generally not rugged enough, or suitable for stamping clear identifiable indicia on metal product. An example of such a printer is shown in U.S. Pat. No. 3,141,403 Brown et al which has spring loaded characters mounted circumferentially on the printing wheel. Also, means are known for indexing of stamp characters in devices which press the character into metal product while it is stationary. An example of controls for such devices is shown in German Design Patent No. 7,722,066 and in the corresponding published utility application, Offenlegungsschrift No. 2,731,849. Clearly, such devices are not suitable for repetitive stamping operations on moving product.
It is therefore a primary object of this invention to provide an indexable apparatus for repetitive stamping of hot metal products.